fix(bug): Fix form validation does not work in Kotlin.

[Yue-plus]

Description

• -Xjsr305=strict: This argument changes how the Kotlin compiler handles nullability annotations. The strict mode means that the compiler will strictly check nullability annotations and give a warning or error when it finds a problem.
• -Xemit-jvm-type-annotations: This argument makes the Kotlin compiler emit JVM type annotations into the bytecode.

Fixes #2343

Type of change

• Bugfix
• Feature

Checklist

• I have read the contribution guide: https://vaadin.com/docs/latest/guide/contributing/overview/
• I have added a description following the guideline.
• The issue is created in the corresponding repository and I have referenced it.
• I have added tests to ensure my change is effective and works as intended.
• New and existing tests are passing locally with my change.
• I have performed self-review and corrected misspellings.

Additional for Feature type of change

• Enhancement / new feature was discussed in a corresponding GitHub issue and Acceptance Criteria were created.

[CLAassistant]

All committers have signed the CLA.

[CLAassistant]

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
0.0% Duplication on New Code

See analysis details on SonarCloud

[Yue-plus]

I apologize for my previous misunderstanding of the Groovy programming language. I was not aware that Groovy allows direct assignment to lists without the need to call the addAll method. I have tested these changes locally and confirmed their correctness. Please review this PR again, thank you.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 92.60%. Comparing base (f7b7546) to head (69a524e).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2529   +/-   ##
=======================================
  Coverage   92.60%   92.60%           
=======================================
  Files          85       85           
  Lines        3164     3164           
  Branches      775      775           
=======================================
  Hits         2930     2930           
  Misses        183      183           
  Partials       51       51           

Flag	Coverage Δ
unittests	92.60% <ø> (ø)

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